I suggest to pay attention to the word "IMPORT" in the topic title. The problem in this case is not to edit an existing map. The problem is that on the basis of one map to make another. I.e. the result should be 2 maps, original and imported.

But the last locally-stored maps that are already available to import. Because, the topic can be closed (until the bug not appear again).

Yes, you can close, because the cards I posted on steam and can import from there, and the bug with new maps not playable. P.S. I wonder, what are the pros and cons of Steam Cloud? Can I disable it? But, for example, when you reinstall windows, will I lose the cards and save?